Revelry Supply Drifter Rolltop BackpackThe Drifter is our rolltop backpack, its added storage makes it ideal for those longer adventures. Each bag has a nylon or cotton canvas exterior that has a heavy duty rubber backing. The rubber backing, that is invisible from the outside, works as our first line of defense by creating odor containment and resistance to water. The carbon filter system has 3 separate layers. The two outer white layers are synthetic filters, and the middle layer is